Deployable antennas are desirable in satellite and other space applications. In such applications, it is important for an antenna to be able to fit into a small space, but also be expandable to a fully operational size once orbit has been achieved.
The issue of antenna deployability is particularly important as the size of satellites gets smaller. While the sensors and operating electronics of miniaturized satellites may be scaled to extremely small volumes, the wavelengths of the signals used by such miniaturized satellites to communicate do not scale accordingly. Given that the wavelength of a signal determines the size of an antenna used to communicate that signal, antennas for miniaturized satellites still need to have dimensions similar to those of larger satellites. Moreover, it is desirable to use such satellites over as wide of a signal spectrum as possible.
One approach for a space deployable antenna is disclosed in U.S. Pat. No. 6,791,510 where the antenna includes an inflatable structure, a plane antenna supported by the inflatable structure and a plurality of tensioning cables for supporting the plane antenna with the inflatable structure. When the antenna is initially placed in a satellite that is to be launched, the plane antenna and the inflatable structure are both stored inside a rocket fairing in their rolled or folded states. After the rocket is launched and the antenna is set on its satellite orbit, a gas or a urethane foam is filled into the inflatable structure to deploy the inflatable structure to its shape. The plane antenna, which is in the rolled or folded state, is extended and the tensioning cables pull uniformly on the membrane surface periphery of the plane antenna to extend it into a flat plane without distortions.
Yet another approach for an inflatable antenna is disclosed in U.S. published patent application no. 2014/0028532. The inflatable antenna includes an inflatable dish with a RF reflective main reflector and an opposing RF transparent dish wall. An inflatable RF transparent support member and an RF reflective subreflector extend from the dish wall. When the antenna is inflated, the main reflector and the subreflector oppose each other to reflect RF energy toward each other to form an antenna. A gas or a hardening foam may be used to fill the inflatable antenna.
Despite the existence of such structures, further advancements may be desirable in certain applications to facilitate satellite antenna deployment and achieve desired operating characteristics.